Audio connectors have become ubiquitous the last several years, finding their way into computers, media players, and other electronic devices. These connectors accept audio jacks that may come in at least two types, 3-pole and 4-pole jacks. A 3-pole jack may have two contacts for audio signals, left and right, and an additional contact for ground. A 4-pole jack may add a contact for a microphone.
Audio signals generated by circuitry associated with an audio connector may be provided to the audio connector and passed to an audio jack. The audio signals may then be passed to speakers, headphones, or other devices via the audio jack. The circuitry associated with an audio connector may be encompassed in a device enclosure along with the audio connector.
Audio signals generated by a microphone or other audio equipment external to the device enclosure may be provided to a microphone contact on an audio jack. These signals may then be passed to the audio connector and then to circuitry inside the device enclosure associated with the audio connector.
As an audio jack is inserted into an audio connector, the microphone contact in the audio connector may come into contact with other contacts on the audio jack before the microphone contact on the audio jack reaches the microphone contact on the audio connector. This may cause a clicking noise that appears to be generated by the microphone and is passed to circuitry associated with the audio connector. This noise may be misinterpreted by this circuitry in undesirable ways. For example, a headset may interpret the clicks as an incoming phone call. Thus, it may be desirable to not activate such circuitry until the audio jack is completely (or nearly completely) inserted into the audio connector.
Also, if an audio jack is partially pulled out of an audio connector, the audio signals may be redirected away from the audio jack. For example, a user listening to music on her headphones may find the sound redirected to speakers when she accidentally partially pulls the audio jack out of the audio connector. Thus, it is desirable to prevent this redirection when an audio jack is partially removed from an audio connector.